Percentage calculator. Calculate what is X% of Y, X is what percent of Y, and percentage change between values. Real-time results.
100% browser-based — your data never leaves your device
Calculate percentages easily with three common modes.
Select from 'What is A% of B?', 'Percentage change', 'A is what % of B?', or 'Add/Subtract Percentage'.
Type the required values into the input fields.
Click Calculate or press Ctrl+Enter to see the result.
Your last 5 calculations are saved in the history section below.
What is A% of B?
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Percentage Calculator is a free online math tool that calculate percentages easily with three common modes. It works entirely in your browser — no downloads, no installations, and no server uploads required. engineers, data scientists, students use Percentage Calculator when they need a fast, privacy-respecting way to process math data without installing additional software. It supports capabilities such as what is x% of y?, x is what % of y?, percentage change. Additional features include real-time results. Common use cases include calculating sales tax, discounts, and tip amounts for shopping and dining, determining grade percentages, exam scores, and statistical distributions, computing percentage change for financial analysis and kpi tracking. All processing happens locally using modern browser APIs, which means your data never leaves your device. This makes Percentage Calculator ideal for working with sensitive data, proprietary code, or any situation where privacy matters.
Percentage Calculator is a free online math tool that helps you calculate percentages easily with three common modes. Key capabilities include what is x% of y?, x is what % of y?, percentage change. All processing is done locally in your browser — no data is uploaded, stored, or shared with any server. There are no sign-ups, no file size limits, and no hidden charges. It is commonly used to calculating sales tax, discounts, and tip amounts for shopping and dining.
Select from 'What is X% of Y?', 'X is what % of Y?', or 'Percentage change from A to B'.
Type your numbers into the input fields. The tool accepts decimals and large numbers.
Click Calculate and instantly see your percentage result. Copy it with one click.
| Category | Details |
|---|---|
| Input Limits | Numeric precision: 64-bit IEEE 754 (double) |
| Result precision: Up to 16 significant digits | |
| Supported Formats | Decimal, Hexadecimal, Binary, Octal, Scientific notation |
| Browser Engine |
|
All operations run entirely in your browser using built-in Math APIs. No server uploads, no data storage, and no third-party requests.
Percentage Calculator is ideal when you need to calculating sales tax, discounts, and tip amounts for shopping and dining without installing software or uploading data to a server. Since everything runs in your browser, there is no setup time and no risk of your data being stored on external servers. For one-off tasks and quick processing, Percentage Calculator is faster than setting up a local development environment or using a command-line tool.
No. Percentage Calculator processes everything entirely in your browser using JavaScript. Nothing you type, paste, or upload is ever transmitted to any server. Your data never leaves your device.
Use the 'What is X% of Y?' mode. For example, to find 15% of 200, enter X=15 and Y=200. The result is 30.
Use the 'Percentage change from A to B' mode. Enter the old value as A and the new value as B. A positive result means an increase, negative means a decrease.
Find the percentage of any number quickly.
Calculate what percentage one number is of another.
Calculate the percent increase or decrease between two values.
Results update instantly as you type.
Percentage Calculator is useful in a variety of scenarios across different workflows:
Calculating sales tax, discounts, and tip amounts for shopping and dining
Determining grade percentages, exam scores, and statistical distributions
Computing percentage change for financial analysis and KPI tracking
This mode is great for comparing values — for example, finding what percentage of your budget was spent in a category.
A positive result means an increase, negative means a decrease. Use this for tracking growth rates and returns.
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Chmod Calculator
Convert Unix file permissions between numeric and symbolic formats.
Random Number Generator
Generate cryptographically secure random numbers with custom ranges and count.
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